This invention relates to an integrated circuit providing a high-speed logic gate without the need for Schottky diodes or gold doping and a selectable high impedance output to simulate an open collector.
The use of Schottky diodes requires an extra processing step in the manufacture of an integrated circuit. Gold doping as used in present TTL and LSTTL products is a relatively costly procedure requiring capital equipment not readily available to all integrated circuit manufacturers. TTL and LSTTL devices provide high-speed propagation of pulses. It is an objective of the present invention to obtain high-speed circuitry that can be made without the use cf Schottky diodes or gold doping.
Many applications for integrated circuits require open collector outputs. It is therefore advantageous where an open collector is not provided to have some means of simulating the open collector output.